4.2
Statistical Considerations: Time Series, Missing Data and Interpretation
in Context
Each indicator should be seen in the context of a given country’s individual
circumstances. These include the structure of the economy, changing energy
technologies and new energy options. Transitions or shifts — such as if the country
changes from subsistence farming to commercial farming, if it changes its electricity
supply from small diesel power stations to large hydropower plants, if it moves from
heavy manufacturing to information technology, or if it discovers a large gas field —
can substantially change the value of an EISD. The analysts must take these kinds of
changes into account when interpreting whether an indicator shows progress towards
sustainable development or not. This might mean giving the indicators different
relative importance with changing circumstances.
4.2.1. Time Series
Energy indicators are necessary to evaluate past developments, assess the status of the
energy system, define potential targets and measure progress. Therefore, the snapshot
of information given by the set of indicators at any moment is of limited use. What is
important is how the indicators change over time. It is therefore essential to record
time series of each indicator in a consistent manner.
Time series data are thus indispensable in the evaluation of the effectiveness of
policies in the long run. They permit an evaluation of how a country got to where it is
and which policies are responsible for current trends, whether the country is where it
wants to be and whether it will achieve its proposed targets under proposed policy
choices. The extension of the analysis into the future through the use of scenarios
developed with modelling tools permits a comparative assessment of different policy
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and strategic paths, and more comprehensive monitoring and analysis of sustainable
development trends. To foster an effective debate about national sustainable energy
development policy, the government might wish to disseminate the results of such
trend analysis.
4.2.2. Missing Data
Some relevant data might not exist at all, some might be difficult to find and some
might be scattered around in disparate institutions and government departments. There
might be duplication in data collection, or data might be collected in different units
and on different bases.
It might not be possible to fill in gaps in historical data by ‘re-collection’ of the data,
and it might not be possible to collect all future data required. Some of the missing
data could be estimated by interpolating between the known data. In some cases,
proxies could be used to approximate missing data. For instance, if there were no data
on deforestation specifically resulting from energy use (ENV6), one might be able to
estimate this indicator from the amount of non-commercial fuel used and the total
deforestation resulting from all purposes. Alternatively, data from other countries
might be scaled or adapted. A certain degree of creativity wedded to topical and
statistical expertise and understanding is implied in this exercise.
4.2.3. Interpretation in Context
Most of the social and environmental indicators are unambiguous markers of
progress. For example, if ambient concentrations of air pollutants in urban areas
(ENV2) show lower values than were previously measured, then this is certainly a
sign of progress and an indication that the policies in this area most likely have
contributed to this.
However, this is not necessarily the case with the economic indicators. For example,
if agricultural energy intensity (ECO7) increases, this might be because of a higher
degree of mechanization or because of a structural change in agriculture, such as a
change from one crop to another that requires more energy for its growing, harvesting
and processing. In these cases, changes in the indicators must be considered in the
context of the country’s specific conditions. So used, however, they show the effects
of policy decisions and are useful for evaluating such decisions and designing future
policy.
The analysis and interpretation of the EISD need to be performed within the context
of each country’s energy and sustainable development priorities. As each country is
unique, the results from one country should not necessarily be taken as a standard for
comparison with another country facing different conditions.
The EISD represent a quantitative tool for monitoring progress and for defining
strategies towards a more sustainable energy future. There are a number of issues that
are difficult to quantify or are more qualitative by nature but that need be considered
in decision-making processes and in the formulation of major energy policies. Many
of these non-quantifiable aspects are within the institutional dimension of sustainable
development. Therefore, the results of analysis with the EISD tool need to be put into
a larger policy perspective for effective decision making.
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